This invention relates generally to improvements in medical fluid infusion systems and devices for delivering a selected infusion fluid to a patient. More particularly, this invention relates to an improved and easily manipulated quick-connect coupling mounted in-line with a length of infusion tubing to permit temporary disconnection and subsequent re-connection of an infusion fluid source relative to a patient, without requiring removal of a transcutaneous infusion cannula from the patient.
Medical fluid infusion systems are generally known in the art for use in delivering a selected infusion fluid to a patient. In one common form, a relatively compact infusion pump is adapted to receive a syringe or the like carrying a selected medication for administration to a patient through a length of infusion tubing and a transcutaneously placed infusion cannula. The infusion pump includes a small drive motor for controlled advancement of a syringe piston plunger to administer the medication to the patient. Programmable control means are normally provided for operating the drive motor continuously or at periodic intervals to obtain a closely controlled and accurate delivery of medication over an extended time period. Such infusion pumps are utilized to administer insulin and other medications, with exemplary pumps being marketed by MiniMed Technologies, of Sylmar, California under model designations 504 and 506. See also U.S. Pat. Nos. 4,562,751; 4,678,408; and 4,685,903 pertaining to medication infusion pumps, and U.S. Pat. Nos. 4,755,173; 5,176,662; and 5,257,980 pertaining to infusion sets having a transcutaneous infusion cannula.
Medication infusion pumps and related infusion sets of the general type described above provide significant advantages and benefits with respect to accurate delivery of the medication over an extended period of time. The infusion pump is often designed to be extremely compact and thus may be adapted to be carried by the patient. As a result, the medication can be administered with precision and in an automated manner, without significant restriction on the patient's mobility or life-style.
Despite the many advantages and benefits of compact medication infusion pumps, the patient is required to exercise at least some degree of caution in order to protect against accidental damage to the pump and/or accidental removal of the transcutaneous infusion cannula. In this regard, to safeguard the pump, it may be necessary or desirable to temporarily disconnect the pump from the patient whenever the patient is involved in an activity which might subject the pump to potential damage. Such short-term activities may include, for example, bathing or showering, swimming, or similar activities which might expose the pump to water damage. Similarly, disconnection of the pump may be desirable when the patient participates in certain athletic activities which might otherwise expose the pump to potential impact damage. It is, of course, desirable to promptly re-connect the medication infusion pump to the patient when such activity is concluded.
In the past, temporary pump disconnection from the patient has typically been accomplished by removing the infusion cannula from the patient. Unfortunately, this technique requires subsequent re-placement of the cannula with an insertion needle. Such re-placement of the cannula with an insertion needle must be done under sterile conditions and involves repeated and undesirable needle sticks. Alternative techniques have utilized quick-connect couplings adapted for in-line mounting along the infusion tubing. However, prior quick-connect couplings designed for periodic separation have typically encountered problems with accidental separation of the coupling components, or have otherwise required the application of substantial manual force to separate the coupling components. In the latter case, when substantial force is applied to pull apart the coupling components, there is a significant risk of inadvertently removing the infusion cannula from the patient. In another alternative, temporary pump disconnection can be achieved by temporary removal of the medication containing syringe from the pump, but this approach requires the patient to handle the syringe at the now-unsupported end of the infusion tubing and also presents problems in re-installation of the syringe into the pump.
The present invention is directed to an improved yet relatively simple and safe quick-connect coupling designed to permit temporary disconnection and subsequent re-connection of a medication infusion pump relative to a patient, without requiring high longitudinal separation forces to thereby protect against inadvertent removal of a transcutaneous infusion cannula from a patient.